The present invention relates generally to protective devices for fire hydrants. More particularly, the present invention provides an inexpensive, simple and sturdy mechanism which is highly effective in preventing unauthorized users from opening a fire hydrant and simultaneously provides a device which does not have to be removed prior to authorized use of the hydrant.
The prior art includes a variety of protective devices for fire hydrants. Most of these devices are expensive and must be removed before the fire hydrant can be operated. Some of the prior art devices are difficult to retrofit onto an existing hydrant. Another disadvantage of some of the prior art mechanisms is that the mechanism provides an intermediate member between the operating stub of the hydrant and the authorized tool so that the tool actuates an intermediate member which, in turn, actuates the operating stub. The weakness of such designs is that, if the intermediate member fails for any reason, the hydrant may not be actuated. A significant drawback to virtually all the prior art designs known to the applicant is that precious time is required either to remove a portion of the protective device to gain access to the operating stub of the hydrant or to apply a special tool to the operating stub.
The prior art mechanisms include the Kennedy U.S. Pat. No. 5,383,495 dated Jan. 24, 1995 having a dome which completely covers the operating stub and which requires a special tool to remove the dome. The Leopold et al U.S. Pat. No, 4,566,481 dated Jan. 28, 1986 teaches another mechanism which totally encloses the operating stub and requires a special and expensive operating wrench in order to actuate the hydrant. A further drawback of the Leopold design is that it does not lend itself to being retrofitted onto existing fire hydrants. The Oakey U.S. Pat. No. 4,182,361 dated Jan. 8, 1980 teaches another device completely enclosing the actuating stub. The Franceschi U.S. Pat. No. 3,935,877 dated Feb. 3, 1976 teaches a dome-shaped mechanism which completely covers the actuating stub and which requires the use of a cumbersome and expensive operating tool. The Diaz U.S. Pat. No. 3,709,249 dated Jan. 9, 1973 teaches a dome-shaped mechanism which requires a special actuating tool to engage a flat intermediate surface 34 which, in turn, engages the operating stub of the hydrant. A device sold by McGard Company under its registered trademark "Intimidator" includes a dome covering the operating stub, requires a special tool, and is relatively expensive.
The present invention provides an inexpensive, sturdy effective shield which may be readily retrofitted onto existing hydrants, which does not have to be removed in order to actuate the operating stub of the hydrant. The device of the present mechanism in its preferred embodiment is designed to allow fire departments and water districts to utilize standard and commercially available operating tools to actuate the hydrant stub without removing the shield.
A primary object of the invention is to provide a sturdy, yet inexpensive, protective shield for fire hydrants which may be readily applied to existing hydrants and which does not have be removed prior to actuating the hydrant.
Another object of the invention is to provide a protective shield for fire hydrants which allows actuation of the hydrant by standard hydrant wrenches without removal of the shield and which also prevents actuation of the hydrant by standard pipe wrenches.